Biomedical subjects
D Chavasse
Publications and source records attributed to D Chavasse.
Predicting high-risk years for malaria in Colombia using parameters of El Niño Southern Oscillation.
The interannual variation in malaria cases in Colombia between 1960 and 1992 shows a close association with a periodic climatic phenomenon known as El Niño Southern Oscillation (ENSO). Compared with other years, malaria cases increased by 17.3% during a Niño year and by 35.1% in the post-Niño year. The annual total number of malaria cases is also strongly correlated (r = 0.62, P < 0.001) with sea surface temperature (SST) anomalies in the eastern equatorial Pacific, a principal parameter of ENSO. The strong relation between malaria and ENSO in Colombia can be used to predict high and low-risk years for malaria with sufficient time to mobilize resources to reduce the impact of epidemics. In view of the current El Niño conditions, we anticipate an increase in malaria cases in Colombia in 1998. Further studies to elucidate the mechanisms which underlie the association are required. As Colombia has a wide range of climatic conditions, regional studies relating climate and vector ecology to malaria incidence may further improve an ENSO-based early warning system. Predicting malaria risk associated with ENSO and related climate variables may also serve as a short-term analogue for predicting longer-term effects posed by global climate change.
Scope for fly control as a diarrhoea intervention in Pakistan: a community perspective.
Clinic records show childhood diarrhoea to be an important health problem in the North West Frontier Province of Pakistan, particularly during the Spring months when the density of houseflies is highest. Fly control measures during this season may reduce the incidence of diarrhoea. By using participatory research tools during meetings with 61 mothers it was found that diarrhoea was perceived to be the biggest health problem faced by their young children and, after mosquitoes, houseflies were considered to be the biggest insect pest in the domestic environment. It was found, during in-depth interviews with a separate group of mothers, that flies were considered to be the principal cause of diarrhoea. If fly control is shown to reduce childhood diarrhoea then long term community based fly control may be feasible because the community is likely to support efforts resulting in reduced fly density. Treatment of diarrhoea, in the study area, was based on a combination of local remedies and commercially produced drugs. It was found that following an estimated average of 4.2 and 0.8 visits per child year to the local dispenser and specialist, respectively, an estimated average of $9.4 per child year was spent on diarrhoea treatment alone. A reduction in diarrhoea incidence as a result of fly control would result in economic gains over and above health gains. The preliminary results presented in this paper support the need to investigate the impact of fly control on childhood diarrhoea in Pakistan and this would have relevance for other developing countries.